Hello everyone!
So here's the thing. I've been on a controlled medical diet for months. Every month, I gained 1-1'5 kg, it was almost mathematical. I was so frustrated that when X-mas holidays came I decided to just blow it all up and eat whatever I wanted and stay on the couch for as long as I felt like (I was really stressed out, I'm doing a master course which is horrible, tons of work, bad organization... so on).
I weighted myself after the holidays. I'd lost 1'5 kg. At first I thought it would be muscle mass, but my clothes felt looser around my waist. My face also looked thinner (like I had de-puffed, even though I'd had tons of fizzy drinks and champagne).
Then I began my classes once again, and I've gained that 1'5 kg back, even though I'm eating properly now and doing more exercise than back then; which leads me to believe the reason why I have been gaining weight non-stop since the beginning of my course is STRESS.
What do you guys think? Anybody knows if I'm going crazy or is this actually possible?

Yep. One word for you: cortisol. It's known as the "stress hormone" and, while I am not sure of the exact biological mechanisms, it is directly linked to weight gain (or slowing weight loss). It's also at least part of the reason that lack of sleep hampers weight loss as well; sleep deprivation causes increased production of cortisol.

__________________Cassie

And now that you don't have to be perfect, you can be good.
-John Steinbeck